Solar Driven Air Conditioning – A Huge Game Changer!

Since our whole mission is all about how to build green homes I have been very negative about air conditioning due to it being such an energy pig which to say the least conflicts with green building principles. However of those that choose to live close to sea level there is without question those who feel they just cannot exist without cooling down their environment to some degree. I understand and appreciate that fact but it has always been a serious trade off for me in achieving the green goal while saying air conditioning in the same breath. Problem solved!

With that said we do have to look at the whole formula that affects a home being hot or cool. Needless to say to achieve anything reasonable efficient homes have to be insulated which of course we are adamant in doing so. Along with that using intelligent tropical design methods one can and does drastically reduce A/C demands with simple things like no sun exposed glass, high ceilings etc. Most homes I see here usually fail miserably in design, methods and materials hence it becomes one serious uphill battle in trying to cool of the beast without being raped and pillaged by ICE. Kind of like trying to float a submarine with a screen door on it.

Now the good news that brings about this blog post is solar powered A/C units have entered the market in the USA and a company has brought the distribution and support of such products to Costa Rica. They claim to reduce energy costs by 80% using both the solar power during sun hours as well as a variable speed split unit to reduce consumption from the grid in the evenings or transition periods of the day. Now obviously if the sun is a blazing this is when you meet your peak demand for A/C which happens to coincide with peak production of solar power. A match made in heaven. I suspect most clients who are just trying to drop the temperature to a tolerable level not turn their home into a meat cooler would find that if you leave the peak sun hours with the temperature of the home tolerable that the need for evening cooling is pretty much gone. Hence I suspect many of our clients would not even use their units in the non-solar hours of the day hence actually zero power from the grid would be required. Also aiding this is our insulated walls not providing the pizza oven effect that concrete homes so wonderfully provide. Where one is retrofitting one of these submarines the story is going to be substantially different. However that does not apply to our homes or clients on the whole.

I had seen an add in the Howler magazine of the Guanacaste about two months ago and thought, hell that is interesting I have to investigate that, then one of our new clients brought my attention to the actual manufacturer, Hotspot. I contacted them and they referred me to the Costarican company that represents them here which was one and the same whose add I had read. Within the next month they are doing a demonstration of a model unit set up in Flamingo that I will be going to see in operation to come up with my final assessment.

The split units run $5,000 with all the solar side included and installed in a home. That is a reasonable price as compared to what a conventional split costs then adding in the solar side as well as installation. However the big point is the ROI on this unit will be great as compared to the horrific power bills that such will avoid as well as enhancing the attractiveness to the home such is installed in. We have quite a number of clients who want to do vacation rentals of their homes when they are not using them. In the rental market A/C is very critical in being able to get the best clients who choose not to rent without A/C. However one huge problem with some tourists/renters is that they just do not give a shit about your power bill sucking you dry! So they will leave a unit running with doors and windows wide open hence really ugly bills follow and the ROI on your investment goes into the sewer. Well with the solar unit you kill two birds with one stone, you attract the best clients but without getting mortgage payment sized electrical bills. On that basis the cost per unit is actually quite reasonable to excellent. They say one unit will service up to 750 ft2 however I have to say I think that is a wild guess because home design and quality of the construction will so drastically affect how many BTU’s it is going to take to cool down any given space. However with how we build and design in the first place I suspect the numbers may even be better than their estimate. For those who only want to control bedrooms these units will more than handle any bedroom option.

This will drastically affect what has been our design parameters especially in near sea level locations that are both much hotter plus often do not have much in the way of air movement which so drastically affects the comfort level of the home. With this as a new tool in our box we will adjust how we would have otherwise carried out the design process and options provided to our clients. Eg. Instead of full flow ventilation we would install windows/ventilators that can be opened or closed depending on the desire for A/C assist in the moment or not. For example windows closed during the day but late in the afternoon the windows open up and the A/C gets shut off so as to enjoy that often perfect temperature of the much cooler evening hours plus giving way to the fresh air flowing into the home along with the wiff of the Ylang Ylang fragrance floating into the home with the natural air flows. You would not be coming home to an oven of pent up heat or trying to cool down the home in the evenings you would be starting with a comfortable home hence the transition into evening hours is immediate and pleasant.

A note back from one of our clients within hours of my posting this article made me realize I forgotten another big factor in this decision. A menace called DUST!!! If your home is near a dirt road and even worse a dirt road in the Guanacaste we simply can’t deny the fact that a home’s comfort is seriously affected when living for months of the year in the middle of a dust bowl. Not fun experience and certainly limits those wide open spaces for ventilation as an option when you are getting choked to death. I often look at homes built here parked right beside busy dirt roads and just shake my head as to why anyone would want the noise, dust and security issues that come from what I would call simply stupid home placement. Two of these issues can be addressed by having an A/C system included in the building plans. Now I still do not agree with central air systems for three reasons A) there is no solar solution for such at this time and they are less efficient in the first place B)tropical homes have no need for a ductwork system in a home unlike up north where we simply tag an A/C unit onto the already needed heating system hence the cost is not near as big of a jump C) UGLY FACTOR, it is much harder to design a home and hide these systems in a tropical design since many things can be said about ductwork but beautiful is definitely not one of them. With splits of this nature a home can easily be zoned using several units separating various sleeping areas from common living areas thereby running what is needed when and avoiding unnecessary use especially during off peak solar hours.

As an interesting confirmation of what I see as the significant benefits of such units this client also confirmed that if he did not have an air conditioned area of the home his mother simply would not come to visit him in the tropics. I could care less about the merits of such a position one way or another but what it does clearly prove is that there is indeed a significant portion of perspective vacation rental clients out there that have the exact same attitude. If one avoids A/C they also avoid access to that whole group of what could well be great clients. Even if we ignored the fact that these units operate so economically the big picture is how much revenue does one loose if you eliminate an entire group of perspective clients based on this one feature of your property. Obviously when you are using the property you also get the benefits of the added comfort.

All in all this is a real game changer in how A/C has been done and finally with a serious dose of sanity and a big leap forward into this century. I will keep you posted as this product develops and I see such in action in person.

About Trevor

I have lived in Costa Rica for 14 years and have been active in real estate development over that period and construction in general. I am a qualified Journeyman carpenter and cabinetmaker from Canada. My current focus project is building custom green homes and housing packages all built out of Magnesium Oxide SIPs.

Hello Trevor,
I am curious if the solar air conditioners are being used there yet. It is a great idea. But there are lower cost options now. Please send me an email and I would like to discuss the possibilities with you. I have researched the solar air conditioners. At the time you read the article, it made sense. But now there are much cheaper and more cost saving ways to tackle this beast.

Hello Jon,
I read with interest your email to Trevor in which you made the comment “there are much cheaper and more cost saving ways to tackle this beast” in regard to solar A/C.
I would be interesting in knowing what your research has uncovered in this regard and your opinion on the options that are not only available in Costa Rica but also economically viable for installation and use there.
If you don’t mind sharing please respond at your convenience.
Thanks
Kelly

Hi, i am the distributor for coolroi.com in Costa Rica. If you need solar AC,With prices way lower that what they are trying to sell on the other page you can contact me 7222 1272 solarac.cr@gmail.com I have presentation in english and spanish